Interactive Effects of Selenium, Zinc, and Iron on the Uptake of Selenium in Mycelia of the Culinary-Medicinal Winter Mushroom Flammulina velutipes (Agaricomycetes).

The present study for the first time addressed whether the simultaneous presence of selenium, zinc and iron may have effects on the selenium uptake in the mycelia of the winter mushroom (also known as enoki), Flammulina velutipes. Response surface methodology was used to optimize concentrations of selenium, zinc and iron in the range of 0 to 120 mg L-1. The findings showed that application of selenium, zinc and iron (singly, in pairs, or triads) significantly enhanced the selenium accumulation in the mycelia. The highest amount of the selenium accumulation was observed when selenium (60 mg L-1) and zinc (120 mg L-1) were applied into submerged culture media, concurrently, leading to an 85-fold and 88-fold increase in the selenium content of the mycelia compared to that of the mycelia treated with selenium only and untreated mycelia, respectively. In addition, accumulation of selenium into the mycelia had no deteriorative effects on the mycelial biomass. The findings presented in this study may have implications for daily nutrition and industrial bioproduction of mushroom mycelia enriched with selenium.

Lentinan and ß-glucan extract from shiitake mushroom, Lentinula edodes, alleviate acute LPS-induced hematological changes in mice.

Objectives: Immunomodulatory activity of ß-glucans of shiitake mushroom (Lentinula edodes) has been known. We investigated whether ß-glucans from L. edodes would attenuate the acute effects of lipopolysaccharides (LPS) on peripheral hematological parameters in mice. Materials and Methods: An in-house ß-glucans extract (BG) prepared from fruiting bodies of shiitake mushroom L. edodes was chemically measured and characterized using spectrophotometry and HPLC. Male BALB/c mice directly inhaled aerosolized LPS of 3 mg/ml and were treated with BG or commercial ß-glucan (known as lentinan; LNT) (10 mg/kg bw) at 1 hr before or 6 hr after LPS inhalation. The blood samples were collected by cardiac puncture from euthanized mice at 16 hr post-treatment. Results: The results showed a significant reduction in levels of blood parameters, including red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), and platelets (PLT); and a significant increase in blood lymphocyte counts in LPS-treated mice as compared with the control mice (P≤0.05). Total white blood cells, neutrophils, and monocyte counts did not show any significant difference among the groups. Treatment of LPS-challenged mice with LNT or BG significantly increased the levels of RBC, HGB, HCT, and PLT; and reduced blood lymphocyte counts as compared with LPS-treated mice (P≤0.05). Conclusion: These findings suggest that ß-glucans from L. edodes might be effective in attenuating the effects of inhaled LPS on peripheral blood parameters. Thus, these findings might be useful in acute inflammatory diseases particularly pulmonary infectious diseases in which the hematological parameters would be affected.

Improvement and Characterization of Naturally Occurring Folate Compounds in Fruiting Bodies of Culinary-Medicinal Winter Mushroom, Flammulina velutipes (Agaricomycetes).

Edible mushrooms are among food sources containing natural folate compounds. However, little is known about how the content of folates in edible mushrooms may be improved. This study aimed to enrich Flammulina velutipes with higher levels of folates and to characterize patterns of the bioconversion of folates in the fruiting bodies. A convenient method was developed to treat a lignocellulosic substrate with synthetic folic acid. Folate compounds in the fruiting bodies grown in folic acid-treated substrates were evaluated relative to those in untreated substrates. Reverse phase high-performance liquid chromatography revealed different patterns of changes in levels of unsubstituted and substituted folates. While there was an approximately 15-fold and 8-fold increase in 5-formyl tetrahydrofolate and 5-methyl tetrahydrofolate, respectively, the most inconsistency was seen in the tetrahydrofolate content. There were also differences in the level of folate derivatives between commercial and native F. velutipes mushrooms. Since F. velutipes mushrooms can be consumed raw, the enriched mushrooms can be used as a dietary source to meet adult requirements for the daily uptake of natural folates.

Toxicity and Nutritional Assessment of Extracts of Medicinal Tiger Sawgill Mushroom, Lentinus tigrinus (Agaricomycetes), a Newly Domesticated in Iran.

Information on the biosafety of tiger sawgill mushroom, Lentinus tigrinus, is limited and controversial. In the present study, the toxicity of a native L. tigrinus strain was evaluated in both cell cultures and mice. In addition to proximate analysis, the amino acid composition and the substrate-dependent uptake of elements were also evaluated. The mushroom (dry weight) had 7.53 ± 0.11% ash, 4.23 ± 0.23% lipid, 13.4 ± 0.04% fiber, 74.84 ± 0.38% total carbohydrate, and 4.16 ± 0.08 (mg GAEs/g) total phenol. Lysine was found at the highest amount among the L-amino acids determined in the L. tigrinus soluble protein. Comparison of the elemental profile of L. tigrinus with that of the substrate demonstrated a great capacity for absorption of K, P, S, and Mg elements, while the Na uptake was low. Neither the substrate nor the mushroom contained toxic elements beyond the standards of the joint FAO/WHO. The viability of normal human and mouse-derived cells was not influenced by the extract up to 250 µg/mL, where 70% of cancerous PC3 and MCF-7 cells were killed. Selectivity index analysis suggested that the L. tigrinus extract was selective only against MCF-7 cells. The extract also did not affect mice treated orally or via i.p. injection, while i.v. injection caused some mortality in mice with an LD50 of 47.19 mg/mL. In conclusion, L. tigrinus may be considered a source of macronutrients and micronutrients with a selective anticancer activity, while it is much less likely to have detrimental effects on humans at low serving levels.

Agronomic and environmental factors affecting cultivation of the winter mushroom or Enokitake: achievements and prospects.

The global interest in production of the winter mushroom or Enokitake (Flammulina filiformis previously known as Flammulina velutipes) is increasing owing to its nutritional and medicinally important bioactive compounds along with a marketable texture and flavor. This review presents the state of knowledge on achievements in solid-state cultivation and submerged cultures of Enokitake and how they are influenced by environmental factors and agronomic characteristics. A wide range of basic lignocellulosic substrates and supplementations have been reviewed in order to formulate an efficient and locally available substrate. Domestication of wild types of Enokitake and its economic and research implications are also discussed. Besides, the influence of environmental and agronomic factors on production and efficacy of the most important biologically active metabolites of Enokitake in both solid-state cultivation and submerged cultures has been discussed. Some of shortcomings of studies reporting cultivation of Enokitake are described and their contribution to future prospects is also discussed in this review.

Antioxidant capacity of several Iranian, wild and cultivated strains of the button mushroom.

The white button mushroom, Agaricus bisporus, is the most commonly grown mushroom in Iran; however, there is a significant shortage of research on its antioxidant activity and other medicinal properties. The aim of this study was to evaluate antioxidant capacity of the methanolic extracts from four cultivated strains and four Internal Transcribed Spacer (ITS)-identified, Iranian wild isolates of A. bisporus. Evaluations were made for total phenols, flavonoids and anthocyanins, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. Overall, results showed that all the wild isolates exhibited significantly lower DPPH-derived EC50, compared to the cultivated strains (p < 0.05). A relatively high relationship was observed between total phenols and flavonoids or anthocyanins (r(2) > 0.60). However, these constituents could not statistically differentiate the group of wild samples from the cultivated ones, and there was low correlation with the DPPH-derived EC50s (r(2) < 0.40). In conclusion, comparisons showed that wild isolate 4 and cultivated strains A15 and H1 had higher antioxidant capacity than the others (p < 0.05). This result identifies these mushrooms as good candidates for further investigation.

Antioxidant capacity of several Iranian, wild and cultivated strains of the button mushroom

The white button mushroom, Agaricus bisporus, is the most commonly grown mushroom in Iran; however, there is a significant shortage of research on its antioxidant activity and other medicinal properties. The aim of this study was to evaluate antioxidant capacity of the methanolic extracts from four cultivated strains and four Internal Transcribed Spacer (ITS)-identified, Iranian wild isolates of A. bisporus. Evaluations were made for total phenols, flavonoids and anthocyanins, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. Overall, results showed that all the wild isolates exhibited significantly lower DPPH-derived EC₅₀, compared to the cultivated strains (p < 0.05). A relatively high relationship was observed between total phenols and flavonoids or anthocyanins (r² > 0.60). However, these constituents could not statistically differentiate the group of wild samples from the cultivated ones, and there was low correlation with the DPPH-derived EC₅₀s (r² < 0.40). In conclusion, comparisons showed that wild isolate 4 and cultivated strains A15 and H1 had higher antioxidant capacity than the others (p < 0.05). This result identifies these mushrooms as good candidates for further investigation.